Flows of Russian gas to four European Union countries were below normal levels on Saturday following Moscow's decision to cut off supplies to Ukraine in a pricing dispute on January 1. Gasprom, meanwhile, has accused Ukraine of dragging its feet in the negotiations over disputed gas contracts and no talks were in sight to resolve the matter.

Gazprom deputy chief Alexander Medvedev spoke to reporters in Prague today, repeating an earlier claim that Ukraine is siphoning off some 35 million cubic meters of Russian gas each day. He also criticized Kyiv for failing to send negotiators to Moscow, saying the situation was "absolutely unacceptable".

Medvedev also said Gazprom was ready to fulfill its commitments to the European Union, and urged Ukraine to fulfill its commitments as a transit country.

Russia cut gas deliveries to Ukraine on Thursday, after a long-running price dispute. But Russia has continued to send gas to its Western European customers through Ukraine.

Ukraine has fiercely denied allegations that it is stealing any of the gas, adding that Russia has reduced its deliveries.

On Friday, the European Union demanded an immediate resumption of Russian natural gas to EU countries, as European countries began to suffer from reduced gas supplies.

Europe gets a fifth of its has from pipelines across Ukraine. Some European Union members, such as Hungary and Romania, said they were feeling the impact. Bulgaria's Bulgargaz operator joined energy firms in Poland, Romania and Hungary in saying they had noted falls in supply, although gas flows to Germany, Europe's biggest economy, were not affected. The EU said it would call a crisis meeting in Brussels on Monday.

Talks between the two sides broke off on December 31 and Gazprom cut off gas supplies to Ukraine the next day. Europe has enough gas stockpiled to manage without Russian supplies for several days. However, It could face difficulties if the dispute is not resolved within weeks, especially if cold weather drives up demand.